Tunnel boring apparatus

ABSTRACT

A TUNNEL BORING APPARATUS IS DISCLOSED IN WHICH AN OUTER TUBULAR SHIELD SUPPORTS AN INNER SHIELD FOR RECIPROCATION ADJACENT ITS FORWARD END WITH A ROTARY CUTTING HEAD BEING MOUNTED ON THE FORWARD END OF THE INNER SHIELD AND WITH THE INNER SHIELD AND CUTTING HEAD BEING MOVABLE BY A PLURALITY OF POSITIONING CYLINDERS REARWARDLY TO BE COMPLETELY ENCLOSED WITHIN THE OUTER SHIELD BUT ALSO BEING MOVABLE TO AN EXTENDED POSITION IN WHICH THE CUTTING HEAD IS ENTIRELY EXTERIOR OF THE OUTER SHIELD? ANOTHER ASPECT OF THE INVENTION RESIDES IN THE PROVISION OF EXTENDABLE WING TEETH ON THE ENDS OF THE CUTTING BARS ON THE CUTTING HEAD MOVABLE TO AN EXTENDED POSITION IN WHICH THEY TRAVERSE A PATH HAVING A DIAMETER LARGER THAN THE DIAMETER OF THE OUTER SHIELD? ANOTHER ASPECT OF THE INVETION RESIDES IN THE ROTATIONAL DRIVE TO THE CUTTING HEAD BEING PROVIDED BY AN OUTPUT DRIVE MOTOR ENGAGING THE PERIPHERY OF A RING PINION ON THE CUTTER HEAD AT A POSITION ADJACENT THE WALL OF THE INNER SHIELD.

June 27, 1972 R. L. HOUSE TUNNEL BORING APPARATUS m l T t w. 8 V m m S S t e 8 mm M A on o 2 3 w w 4, 8

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2055 RT L. House June 27, 1972 R. L. HOUSE TUNNEL BORING APPARATUS 4 Sheets-Sheet 2 Filed July 20, 1970 INVENTOR Wasm ATTORNEYS June 27, 1972 L, HOUSE TUNNEL BORING APPARATUS I N VENTOR ATTORNEYS 4 Sheets-Sheet 5 205521 LHouse Filed July 20, 1970 R. L. HOUSE TUNNEL BORING APPARATUS June 27, 1972 4 sheets sheet 4.

Filed July 20, 1970 INVENTOR CD ATTORNEYS United States Patent Oflice 3,672,726 Patented June 27, 1972 3,672,726 TUNNEL BORING APPARATUS Robert L. House, RR. 5, Box 22-4, Bloomington, Ind. 47401 Filed July 20, 1970, Ser. No. 56,253 Int. Cl. E290 29/00 US. Cl. 299-31 Claims ABSTRACT OF THE DISCLOSURE A tunnel boring apparatus is disclosed in which an outer tubular shield supports an inner shield for reciprocation adjacent its forward end with a rotary cutting head being mounted on the forward end of the inner shield and with the inner shield and cutting head being movable by a plurality of positioning cylinders rearwardly to be complete ly enclosed within the outer shield but also being movable to an extended position in which the cutting head is entirely exterior of the outer shield; another aspect of the invention resides in the provision of extendable Wing teeth on the ends of the cutting bars on the cutting head movable to an extended position in which they traverse a path having a diameter larger than the diameter of the outer shield; another aspect of the invention resides in the rotational drive to the cutting head being provided by an output drive motor engaging the periphery of a ring of the inner shield.

This invention is in the field of earth working equipment and is specifically directed to a boring machine for tunnelling beneath the surface of the earth. Moreover, the subject invention is directed to a tunnelling machine capable of tunnelling through a Wide variety of geological formations.

A wide assortment of machines for enabling the digging of tunnels have been proposed by those skilled in the art. Unfortunately, the prior known devices for this purpose have suffered from a number of deficiencies. For example, many of the prior known devices have been overly complicated and have been consequently expensive to manufacture and maintain. Moreover, a number of the prior devices have been diflicult to directionally control in that they tend to veer downwardly when tunnelling through soft or porous earth due to the substantial weight of the rotary cutting head normally carried on the forwardmost portion of the machine. These and other deficiencies of the prior known tunnelling devices have created a need for a simple and reliable tunnelling machine which is capable of maintaining exact directional control regardless of the type of formation through which the machine is tunnelling.

Therefore, it is the primary object of this invention to provide a new and improved tunnelling machine that is economical to construct and maintain and is also functionally superior to prior known machines.

Obtainment of the object of this invention is enabled through the provision of a tunnelling machine formed with an outer tubular shield which has an inner tubular shield mounted on its interior for axial reciprocation by means of hydraulic cylinders connecting the two shield members. The inner shield also provides support for a drive motor means which engages a rotary cutting head supported on the forward end of the inner shield. The cutting head is supported by unique bearing means on the forward end of the inner shield and the inner shield and cutting head can be moved forwardly to an extended position in which the cutting head is completely external of the outer shield. Moreover, the inner shield and the cutting head can be angled with respect to the outer shield by control of the hydraulic cylinders connecting the two shield members to provide for accurate directional control of the device. Additionally, the cutting head can be retracted entirely within the confines of the outer shield for use when the machine is tunnelling through soft or porous material in which the weight of the cutting head would tend to cause the machine to veer downwardly as it progresses through the earths formation. However, by retracting the cutting head, the outer shield can be forcefully extended through the soft strata to a position forward of the cutting head to provide additional forward support to prevent downward movement of the head. Consequently, great versatility is achieved by virtue of the inventive construction.

Another feature of the subject invention resides in the construction of the cutting head which is a generally cylindrical member having a plurality of cutter bars on its forwardmost portion with extendable and retractable wing teeth being mounted on each end of the cutter bars to be extended beyond the diameter of the outer tubular shield to enable an easy subsequent forward movement of the outer shield through the bore previously cut by the cutting head. However, the extendable wing teeth members on each end of the cutter bars can be retracted in order to enable the cutter head to be moved inwardly into the interior of the outer shield when boring through softer material.

Another feature of the subject invention resides in the uniquely rugged and trouble-free manner in which the cutter head is supported on the forward end of the inner shield. Specifically, a plurality of roller brackets are provided about the periphery of the inner shield with each bracket supporting a pair of rollers mounted for rotation on radial axes with respect to the shield members. A support disc adjacent the rearmost ends of the cutter head is received between each of the spaced rollers and a third roller is mounted for rotation about an axis parallel to the axis of the tubular shield members for engagement with the outer periphery of the discs.

A conveyor is supported entirely by the cutting head and the inner shield for removing cuttings from the cutting head and for carrying the cuttings to the rear of the outer tubular shield. Additionally, drive to the rotary cutter (cutting) head is provided through a large diameter pinion ring connected to the rearmost end of the cutter head and which is in meshing engagement with a drive gear supported on the inner shield in a position adjacent the wall of the inner shield. Consequently, the interior of the shield members is relatively uncluttered and provides adequate working space and optimum safety for the operator of the device.

These and other advantages of the subject invention will be better understood when considered in light of the following written description and drawings in which:

FIG. 1 is an end view of the preferred embodiment of the invention;

FIG. 2 is a bisecting sectional view of the preferred embodiment;

FIG. 3 is a bisecting sectional view of the preferred embodiment taken along lines 33 of FIG. 2;

FIG. 4 is a sectional view taken along lines 4-4 of FIG. 2; and

FIG. 5 is an exploded perspective view illustrating the main functional components of the preferred embodiment.

.Attention is initially invited to FIG. 2 of the drawings which illustrates the preferred embodiment 20 of the invention in a tunnel boring operation through a geological formation 22.

A tubular outer shiled 24 of cylindrical configuration has a forward end defined by an encircling reinforcing band 26 having a cutting edge on its forward surface. The shield also has a rearward end 28.

A tubular inner shield 30 having an outer or forward end 32 is mounted coaxially Within the outer shield 24 for axial reciprocation in the outer shield in a manner to be discussed hereinafter. Inner shield 30 has a rearward end 34 adjacent to which a plurality of brackets 36 are welded on the inner surface of the shield. Each of the brackets 36 is connected to the outer end of a piston rod 38 reciprocally mounted in a hydraulic cylinder 40. Cylinders 40 are connected to brackets 42 Welded to the inner surface of the outer shield 24. Consequently, actuation of cylinders 40 serves to move the inner shield 30 axially within the outer shield 24 in an obvious manner. The cylinders can be actuated different amounts to cant shield 30 to provide directional control if desired and in a manner that will become more apparent hereinafter.

Guide means comprising a plurality of ribs 44 extending parallel to the axes of shields 24 and 30 are welded to the inner surface of shield 24 and extend between guide ribs 46 for preventing rotation of the shield 30 and for guiding the shield 30 during reciprocation in the outer shield 24. These functions are enabled by virtue of the fact that the parallel guide ribs 46 best illustrated in FIG. define a guide groove 47 between their facing surfaces with one of ribs 44 being received in each of the grooves 47 in an obvious manner.

Cutting head 48 is formed of a main cylindrical outer drum 50 having a forward edge 52 and a rearward termination at a radial annular flange '54 as best shown in FIG. 2. Flange 54 constitutes a radial wall providing a connection between the outer drum 5t) and an inner drum 56 which is also of cylindrical configuration. A ring pinion 58 is attached to the rearmost end of the inner drum 56 for receiving the output drive rom a driven pinion 60 supported in casing 62 attached to the inner Wall of the inner shield 30 and driven by motor means 64 through a coupling 66. A step-down transmission 68 is normally interposed between the motor 64 and coupling 66.

First and second cutter bar members 70 are welded to the forward edge of the main cylindrical outer drum 50 and extend radially outward from an anger 71; additionally, a plurality of teeth 72 are connected to each of the cutter bars 70 in an obvious manner. Additionally, a radially extendable wing tooth 74 is mounted on each end of the respective cutter bars 70. The wing teeth 74 can be pivoted to the extended position illustrated in solid lines in FIG. 1 in which the ends of the teeth extend outwardly beyond the outer periphery of the outer shield 24 or they can be alternatively positioned inwardly in the dotted line position of FIG. 1 in which they are entirely within the confines of the outer surface of the inner shield 30. When in the latter position, the cutting head can be entirely retracted within the interior of the outer shield 24.

Rotary bearing means are provided adjacent the forward end 32 of the inner shield 30 for supporting a rotary cutting head 4-8. The bearing means includes a radial bearing disc 7-6 welded to the outer surface of the inner drum 56 as best shown in FIG. 2 and which provides the bearing surface for supporting the cutting head for rotation. The disc 76 is received in bearing means in the forward end of shield 30 which supports the cutting head 48 for rotation. This bearing means comprises a plurality of roller support bracket members 78 of U-shaped configuration each of which is. welded to the inner surface of shield 30 and each of which supports a pair of spaced rollers 80 each individually bearing against an oposite space of the disc 76 and each of which is mounted for rotation about an axis radial with respect to shield 30. Additionally, a plurality of support rollers 82 are mounted to engage the outer circumference of the disc 76. Therefore, it will be readily apparent that the entire cutting head 48 is supported for free and easy rotation adjacent the forward end of shield 30.

A plurality of bucket plates '84 are mounted on the interior of the outer drum 50 for receiving cuttings from 4 the teeth on the cutter bars 70. Bucket plates 84 on the interior of drum 50 lift the cuttings upwardly and gravitationally drop them onto a conveyor belt 86 supported by a conveyor frame 88. Shield 89 mounted on the forward end of frame 88 serves to insure that all of the cuttings are deposited on the conveyor in the manner best illustrated in FIG. 1. A reverse spiral flange 89 extends outwardly from the outer surface of drum '50 and serves to push any cluttings that should be external of the drum 50 to the left as viewed in FIG. 3 for insuring that such cuttings are eventually deposited on the conveyor by the bucket plates 84 rather than merely passing to the interior of the shields over the surface of drum 50.

Conveyor frame 88 has a cross bracket 90 apertured at 92 to be received on a pivot support pin 94 coaxial with the auger 7.1 on the rotary cutting head. Therefore, it will be apparent that cuttings falling from the bucket plates 84 will be deposited upon the forward end of conveyor belt 86.

Conveyor belt 8 6 is driven by motor means adjacent its rearmost end. Additionally, conveyor support brace members 102 are connected to the frame 88' on one end and to the inner sleeve 30' on the other end for providing support for the discharge end 104 of the conveyor. Therefore, it will be apparent that the conveyor is entirely supported by the inner shield 30 and consequently moves as a unit therewith upon actuation of the cylinders 40.

Push brackets are welded to the inner surface of the outer shield 24 and are connectable to any force providing means such as rods 112 of a hydraulic cylinder that would be connected to an expansion ring or the like imrnovably positioned in engagement With the tunnel Wall or other fixed means behind the rear most end 28 of the outer shield 24. The entire outer shield assembly 24 can be forced forwardly by actuation of the power means connected to rods 112 for enabling the shield to be moved through relatively soft or porous strata ahead of the rotary cutting head 48 if such should be desired. When inserted in such soft strata, the forward end of the outer shield 24 will provide support for the entire device to resist any downward movement of the tunnelling assembly which would be caused by the heavy weight of the cutting head assembly. The entire forward movement of the device can be effected by actuation of the power means 112 so that the entire structure is moved forwardly with the cutting head removing the material in front of the apparatus. However, the cutting head could also be advanced during a cutting operation solely by means of cylinders 40 in some circumstances. For example, the cylinders 40 could be extended to their maximum extent with outer sleeve 24 being fixedly held in position; the power means connected to members 112 would then be actuated to move the outer sleeve forward following depressurization of cylinders 40 in order that the outer sleeve would catch up with the inner sleeve and the cycle could then be repeated. A disc means 104' extends outwardly through an aperture in the outer shield for embedded engagement with the surrounding tunnel wall for preventing rotation of the outer shield.

Moreover, it should be understood that there are at least four hydraulic rods 112 which can be actuated to provide varying forces at their points to the shield assembly 24 so as to enable rods 112 to provide major directional change forces to turn and guide the outer sleeve assembly 24.

Additionally, the sleeve 36 and associated cutting head etc. could be canted somewhat by actuation of cylinders 40 in varying degrees so as to provide a steering effect for the entire device as it is advanced forward by the power means connected to members 112.

Various modifications of this invention will undoubtedly occur to those skilled in the art. However, it should be understood that the spirit and scope of this invention is limited solely by the appended claims.

I claim:

1. A tunnel boring apparatus comprising a tubular outer shield having a forward end and a rearward end, guide means on the interior of said tubular outer shield, a tubular inner shield having a forward end and a rearward end, said tubular inner shield being supported on said guide means for axial reciprocation coaxially with respect to said tubular outer shield, rotary bearing means adjacent the forward end of said inner shield, a rotary cutting head supported in said rotary bearing means and having an outer diameter slightly less than the inner diameter of said outer shield, power drive means mounted on the interior of and adjacent to the wall of said inner shield connected to said rotary cutting head and drivingly engaged with said power drive means for drivingly rotating said cutting head, expandable and contractible power means connected between said outer shield and said inner shield for moving said inner shield between a retracted position in which said cutting head is positioned entirely within the confines of said tubular outer shield and an extended position in which said rotary cutting head is positioned forwardly of the forward end of said tubular outer shield, conveyor means extending coaxially along substantially the entire length of said tubular outer shield having a forward end within the peripheral confines of said rotary cutting head for receiving cuttings therefrom and coupling means adjacent the rearward end of said tubular outer shield for connection to power actuated means for moving said tubular outer shield forwardly as a tunnel being bored by said apparatus progresses.

2. The invention of claim 1 wherein said guide means on the interior of said tubular outer shield comprises a plurality of parallel elongated rib members extending outwardly from said tubular inner shield to define a groove parallel to the axis of said tubular outer shield with mating rib members extending from the inner surface of said tubular outer shield being received within said grooves.

3. The invention of claim 2 wherein said rotary bearing means includes a plurality of roller supporting brackets spaced about the forward end of said inner tubular shield, first and second spaced roller members mounted on each bracket, a radial bearing disc on said cutting head received between said first and second spaced rollers and a support roller mounted in each of said roller supporting brackets for rotation adjacent the outer periphery of said radial bearing disc about an axis of rotation parallel to the axis of said tubular outer shield.

4. The invention of claim 3 wherein said cutting head comprises a plurality of cutter bar members radially oriented with respect to said cutter head, a cylindrical outer drum having a forward end to which said cutter bar members are connected, a radial wall extending from the innermost edge of said cylindrical outer drum, an inner drum of diameter less than the diameter of said outer drum connected to said radial wall with said pinion means being mounted on the innermost end of said inner drum.

5. The invention of claim 4 additionally including disc means extending outwardly through an aperture in said tubular outer shield for embedded engagement with the surounding tunnel wall in which said outer shield is located for preventing rotation of said outer shield.

6. The invention of claim 5 wherein said cutter head additionally includes expandable cutter teeth adjacent each end of said cutter bar which when in an extended position extend outwardly beyond the diameter of said tubular outer shield but which when in a retracted position are positioned within the diametrical confines of said tubular outer shield.

7. The invention of claim 1 additionally including pin means coaxially extending from said rotary cutting head, said pin means supporting the forward end of said conveyor and brace means connecting said conveyor to said inner tubular shield and supporting the rearmost end of said conveyor whereby said conveyor is unitarily moved with said inner shield with respect to said outer shield upon actuation of said expandable and contractible power means.

8. The invention of claim 7 wherein said guide means on the interior of said tubular outer shield comprises a plurality of parallel elongated rib members extending outwardly from said tubular inner shield to define a groove parallel to the axis of said tubular outer shield with mating rib members extending from the inner surface of said tubular outer shield being received within said grooves.

9 The invention of claim 8 wherein said rotary bearing means comprises a plurality of roller supporting brackets spaced about the forward end of said inner tubular shield with each bracket supporting first and second spaced roller members between which a radial bearing disc of said cutting head is received and a support roller mounted in each of said brackets for rotation adjacent the outer periphery of said disc about an axis of rotation parallel to the axis of said tubular outer shield.

10. The invention of claim 9 wherein said cutting head comprises a plurality of cutter bar members radially oriented with respect to said cutter head, a cylindrical outer drum having a forward end to which said cutter bar members are connected, cutting teeth on the forward surface of said cutter bars, expandable Wing teeth on each end of each of said cutter bars movable to an extended position in which said wing teeth extend outwardly beyond the diameter of said tubular outer shield and also movable to a retracted position in which said wing teeth are positioned within the diametrical confines of said tubular outer shield and disc means extending outwardly through an aperture in said tubular outer shield for embedded engagement with the surrounding tunnel wall in which said outer shield is located for preventing rotation of said outer shield.

References Cited UNITED STATES PATENTS 3,301,600 1/1967 Pirrie et al. 299-66 X 3,307,876 3/ 1967 Akkerman 299-33 X 3,355,215 11/1967 Haspert et a1. 299-31 X 3,411,826 ll/1968 Wallers et al 2993l 3,413,033 11/1968 Clark 299-56 X MARVIN A. CHAMPION, Primary Examiner R. E. FAVREAU, Assistant Examiner US. Cl. X.R. 102 

